!-------------------------------------------!
!  CFLcondition                             !
!-------------------------------------------!
        SUBROUTINE CFLCON()
        USE BASIC_MOD
        IMPLICIT NONE
        INTEGER:: I,J
        REAL*8::   DT_CONV
        DT_CONV=1.D0
        DO I=1,XCELLS
            DO J=1,YCELLS
                DT_CONV=MIN(DT_CONV,MIN(DX/(ABS(UU(I,J))+CC(I,J)),DY/(ABS(VV(I,J)+CC(I,J)))))
            END DO
        END DO
        DT=CFL*DT_CONV
        END SUBROUTINE